Osmitopsis asteriscoides

This attractive white daisy has been in use for various medicinal purposes for hundreds of years. During spring and early summer many of the wetland areas of the Western Cape are arrayed with dense groups of this aromatic plant in full flower.

DescriptionFast growing, Osmitopsis asteriscoides is a leggy, erect, herbaceous perennial which can grow to 2 m. It is sparsely branched at the base while the upper stems are well branched. The lower parts of the stems are leafless, showing the cracked grayish bark. The aromatic leaves are densely arranged towards the branch ends. The leaves are lance shaped and may be smooth or velvety, 10 – 18 mm wide and 60 – 80 mm long and have a distinctive camphor-like smell. The typical daisy flower heads are grouped on the short upper branches. Each flower head is about 35 mm across, the outer ray florets are white while the central disc florets are yellow. Flowers may be found throughout the year but the main flowering season is in spring and early summer.

The small 3 – 4 ribbed or angled fruit, known as an achene, is dry and brownish and does not have a pappus (a tuft of hairs or bristles) which many of the daisy family have. Each fruit contains a single seed but does not split open to release it.

Distribution and habitatThe swamp daisy is only found growing in the Western Cape. It grows in marshes and seeps on sandstone soils, in an area extending from the Cape Peninsula to the Riviersonderend Mountains. It would be suitable for growing in temperate winter rainfall areas with soils that are damp to wet all year round.

Derivation of name and historical aspectsOsmitopsis is the Latin derivation of “like Osmites” which is a genus which no longer exists. Osmites is derived from the Greek “osme” which means “scent”. The plants have aromatic leaves.

The Afrikaans or Dutch common name “Bels” is derived from “Bellis”, a name commonly used in Europe for the European daisy, Bellis perennis, and which was also applied to two similar looking species in the Cape by early European settlers. Early collectors and botanists applied various scientific names to the plant and a good drawing of it was published in 1739. When “kruie” is added to the Afrikaans name it refers to its use as a herb.

The English names “swamp daisy” and “mountain daisy” make reference to the habitat in which the plant grows, with “swamp daisy” being a far better description.

The Daisy Family, or Asteraceae, is an important plant family in the Cape Floral Region and one of the largest families in South Africa. It comprises 246 genera and 2305 species. There are 9 species in the genus Osmitopsis, all of which occur in the Western Cape.

EcologyThe presence of dense stands of swamp daisy is a very good indicator that an area is either a swamp or seep as they are adapted to grow in wet soils. As the seeds do not have obvious dispersal attachments such as wings or hooks they are more likely to be dispersed by running water which would deposit them in soils which are damp and therefore ideal for growing. Bees have been noted pollinating the flowers but it is very likely that other insects, particularly beetles, will also contribute to this process. If it is burned by fire Osmitopsis asteriscoides will resprout but also grows from seed. If it has been slashed, and sufficient of the thick basal stems remain, it will also resprout.

Uses and cultural aspectsThe leaves are used in a number of ways and have been a traditional Cape Dutch remedy for many years for a variety of ailments. Usage however probably goes back further than the arrival of the Dutch settlers at the Cape. Coughs, hoarseness and other chest complaints were treated with a brandy tincture known as “Belsbrandewyn”as were stomach ache, influenza, fevers, and body pains. It was also used externally to treat cuts, colic and inflammation. Instead of a brandy tincture the leaves could be brewed as a tea and used in the same way. Dried leaves were placed in bags and then applied locally to help relive various conditions. Thunberg, an early explorer in the Cape, claims to have cured paralysis of some kind using this plant.

A volatile oil rich in eucalyptol has been extracted from the leaves which also contain camphor and three sesquiterpenoid lactones. Eucalyptol has long been used to treat catarrh and coughs when taken by mouth and externally as an inhalant and rubefacient. The counter-irritant properties of camphor is well known in the treatment of neuralgia and fibrositis when applied to the skin. It is also used as a treatment for flatulence when taken internally. The sesquiterpenoid lactones may also play a role in the beneficial effects of treatments made from Osmitopsis asteriscoides leaves as they have a wide range of biological activities including action on enzymes.

The swamp daisy is a worthwhile plant to grow in difficult wet areas in a garden, which may also then be harvested for useful home remedies as described above. However it is extremely important that one consults with a suitably knowledgeable practitioner before using any plant as correct identification, methods of application or dosage are vital to ones continuing health. SANBI accepts no liability for use of any plant material described in its publications.

Unfortunately the swamp daisy is not a good cut flower as it drinks copiously and releases the water through the leaves and flowers, wetting the surface on which the arrangement stands. They do not look attractive for long when cut, becoming brown and drooping quite quickly.

Growing Osmitopsis asteriscoides

Collect seed by harvesting the flowers with a small length of stem and leaves when the ray florets (petals) start to turn brown. Spread them out on a cardboard tray and allow to dry completely. Rub the flowerheads and winnow out the fruits (see image).

In March or April sow these smoke-treated fruits containing the seed in trays of a finely sieved mix by volume of 10 parts sand, 4 parts loam soil and 8 parts well rotted pine bark. Germination takes place in about 6 weeks. When large enough pot into bags containing a mix by volume of 10 parts river sand, 6 parts loam soil and 15 parts well rotted compost. Seed trays and bags should remain constantly moist to reproduce the wet nature of the plant's natural habitat.

Cuttings are done from new growth after flowering. Dip in a rooting hormone for soft cuttings and place in trays containing a mixture by volume of 1 part polystyrene beads to 1 part sieved well rotted pine bark. Rooting takes place within 4 – 6 weeks. Keep constantly moist. Pot up as for seedlings above.

After potting up, water the plants with a fungicide as a preventative measure. Plants may be given liquid fertilizer but this is not essential. Harden off both potted seedlings and cuttings under light shade for 4 weeks before putting in full sun. Keep constantly moist.

Plant out in the garden preferably in autumn or spring and into situations which are constantly damp or wet. Water must however not be stagnant but constantly moving through the area.

Young plants should be pinched out to encourage bushy growth. Older, leggy plants can be pruned back very hard after flowering as this encourages dense bushy growth which is more attractive in the garden situation than the natural lengthy growth habit of the plant.